The Fall! Apparently it has a score of 59% on Rotten Tomatoes, which I think is just a crime (even though it could be much worse). It's my very favorite movie.
Also, add me onto the Kung Pow list. Few things have made me laugh so hard as pretty much everything Betty said in that movie.
And I know it has good ratings but a lot of people are really unfair to Mean Girls (usually if they haven't seen it) just because it stars Lindsay Lohan. She's not bad at all in it, and the movie itself is terrific. (It was written by Tina Fey; how could it not be?)
And now, below-average/poorly-rated movies that I think had a certain something, even though I didn't love them:
* Waterworld (it was pretty bad, but the setting had promise; a remake might be fun)
* Robin Hood: Prince of Thieves (remove Costner and it would have been a perfectly decent movie; Alan Rickman was just amazing)
* Reign of Fire (it was fun, it just didn't quite come together enough for me to love it)
* Atlantis: The Lost Empire (same as above; I almost loved it, but it felt very loose somehow)
* Spanglish (the characters needed to be less one-dimensional, but it really wasn't that bad)
* Silent Hill (again, it was fun. Just consider it something separate from the games. I don't think the story from the first game was all that special to begin with either.)
* Hitchhiker's Guide to the Galaxy (it's rated okay, but nerds hate it. I thought it was fantastic; it didn't stick to the book, but none of the adaptations of this story are exactly the same, so give it a break)
And that's pretty much all I can think of. Usually I seem to agree with Rotten Tomatoes for some reason.